1. Field of the Invention
The invention relates to an induction heating coil and a method for melting granules composed of semiconductor material on a plate with an outlet tube. An induction heating coil of this type is required, in accordance with DE 102 04 178 A1, in order to be able to produce a single crystal of semiconductor material with granules as raw material.
2. Background Art
FIG. 4 shows a known induction heating coil in an arrangement during the production of a single crystal. The granules melted with the aid of the induction heating coil flow through an opening in the center of the plate with formation of a funnel-shaped film of semiconductor material into a melt. The melt forms a reservoir which, controlled by a pulling coil, crystallizes to a single crystal while increasing the volume thereof. For the crystal growth to proceed without any disturbances it is important, inter alia, for the film and the adjoining melt to remain liquid. In order to preclude uncontrolled freezing of the film and the melt, a radiant heating system is present. However, such a radiant heating system is complicated and not very efficient because the majority of the radiation impinging on the film is reflected and thus remains ineffective. Furthermore, the film and the melt cannot be heated uniformly because the respective angles of incidence of the radiation differ significantly.